Module 4 Newton's Laws (15 Days)

Module Components

Overview

This unit bundles student expectations that address the analysis of motion (kinematics) as it is described by Newton’s laws.Prior to this unit, students have been introduced to motion in Grades 6–8, as well as during previous units in Physics. During this unit, Newton’s three laws of motion, the knowledge of forces, and the knowledge of the inertial properties of matter provide powerful tools that will be used by students for analysis. After this unit, students will further develop their understanding by exploring motion, forces, and energy as related to the topics of gravity, electromagnetic forces, and waves.STAAR Note: The concepts and skills explored in this unit will address standards associated with the STAAR Physics assessment Reporting Category 1:Force and Motion.

Essential Questions

What are the rules that govern how objects move?What are forces?Can the motion of objects be predicted?

Knowledge & Skills

The student will be able to calculate THE EFFECT OF FORCES ON OBJECTS including, but not limited to:Net forceNet force = (mass)(acceleration)Fnet = maLaw of inertiaThe relationship between mass and inertia using Newton’s 1st lawRelationship between force and accelerationProblems involving force, mass, and acceleration using Newton’s 2nd lawInterpret real-life situation using Newton’s 3rd law.Nature of force pairs between objectsMass vs. weightGravityForce of gravitational attraction between two objects = (universal gravitationconstant) ((mass of 1st object)(mass of 2nd object) /(distance between centers of objects)2)Fg=G(m1m2/d2)Action-reaction pairsElectrostatic forcesFriction forcesCollisionsThe forces acting on an object on an inclined plane

Key Understandings

Students should understand why objects move and react to forces the way that they do.Mass has two properties- gravitational and inertial.Weight is a gravity force.Inertia and forces determine acceleration.Acceleration and forces are vector quantities.Newton’s laws describe the effects of external forces on masses in inertial reference frames.Free-body diagrams are an essential step in the analysis of force-acceleration problems.

Misconceptions

Students may think objects with more mass “push” harder than objects with less mass.Students may think a constant force must be applied to an object for it to remain in motion.Students may think that even without friction, objects in motion would still eventually stop moving.

Key Vocabulary

Newton’s laws of motion – three physical laws that describe the basics of classical mechanicsForce – a push or pull on an objectInertia – the resistance of an object to a change in motionAcceleration – change in speed or direction of the motion of an objectFree body force diagram – a diagram of forces acting on an object

Performance Indicators

Create a free-body force diagram of a 6 kg rock falling off of a 25 meter cliff, and calculate the forces affecting the rock.

Summative Assessments

This module will have a performance indicator as well as the unit assessment and one exam.